Over two million people in the US download health apps onto their smartphones and tablets, with the intent of improving their quality of life. Despit widespread use of these apps, there is relatively little information regarding app user access (do users download health apps and use them more than once), app user engagement (do users follow the app protocols) and app impact on mood, cognition and daily functioning. Our long-term goal is to conduct a future randomized controlled trial investigating access, engagement and impact of two types of mental health apps, apps based on evidence-based therapeutic principles (i.e.: Problem Solving Therapy) and apps based on cognitive neuroscience principles of depression (i.e.: a cognitive training game called Evolution) and compare both to an information only app. Our intent is to conduct this study entirely on mobile devices, in order to investigate access, engagement, and impact in an ecologically valid manner. The purpose of this pilot study is to test the feasibility of conducting our future randomized controlled trial comparing three mobile mental health apps for the management of depressed mood, improvement of cognitive control, and improvement in activities of daily living in people aged 18 and older. Recruitment, consent, randomization, app use and outcome assessment will be conducted entirely on mobile devices. We will recruit 150 people through four different recruitment avenues to determine which avenue results in the most representative sample of our target population (people 18 and older who have symptoms of depression that are interfering with their quality of life). We will also determine the number we need to recruit to have a final sample of 150 people willing to be randomized between the 3 apps and complete an 12-week study of app impact on mood, cognition and function. This pilot will provide information on the completeness of data from a study conducted in this manner, and uncover any other challenges we may face by using mobile devices for data collection, and if we will find differential drop out between app type (e.g.: will more people stop using of the information only app prematurely?). Although we will not have sufficient statistical power to answer questions about comparative effectiveness between the apps, we plan to explore relationships between sample demographics, app use, and improvement in cognitive control on improvements in mood and function.